Pollen morphology of selected species of Cucurbitaceae Juss. from the Cerrado

Pollen morphology of six native and two sub-spontaneous species of Cucurbitaceae found in the state of Goiás, Midwest Region of Brazil were analyzed to understand the palynology and taxonomy of the selected species. Pollen grains were acetolyzed, measured, described, photographed and electromicrographed. SEM was used to analyze exine ornamentation. Pollen grains are monads in Cayaponia podantha Cogn., Ceratosanthes tomentosa Cogn., Luffa operculata (L.) Cogn., Melothria campestris (Naudin) H. Schaefer and S. S. Renner, Momordica charantia L., Wilbrandia hibiscoides Silva Manso or tetrads in Gurania lobata (L.) Pruski and Psiguria umbrosa (Kunth) C. Jeffrey; average size, large or very large in monads and tetrads. The openings ranged from pores in Cayaponia podantha, colpores in other monads and pores in tetrads. Regarding ornamentation, Cayaponia podantha has spiny sexine, Melothria campestris perforated sexine, Gurania lobata and Psiguria umbrosa micro-reticulated sexine, and other taxa have reticulated sexine. Cayaponia podantha and Psiguria umbrosa were first described in this study. Results allowed the distinction between genera, indicating that the pollen morphology contributes to the taxonomic studies and the family is considered eurypalynous. This study provides information that, with other previously published studies, will allow a better understanding of the phylogenetic relationships between these species.